1. Field of Invention
This invention relates generally to medical needle apparatus and methods and particularly to apparatus comprising medical needles which are retracted from an extended position at which the needle is used to a retracted position where the needle is fully withdrawn and encased within a housing for safe disposal. Further, the invention is related to medical products which may only be used once to eliminate cross contamination from one patient to another. More specifically, the invention is related to safety butterfly devices.
2. Prior Art
Problems associated with inadvertent needle sticks are well known in the art of blood withdrawal, transdermal medication injection, catheter emplacement and other medical procedures involving uses of medical needles, especially winged needle apparatus commonly referenced under the general term of butterflies. Ever increasing attention is being paid to needle stick problems due to the contemporary sensitivity to being exposed to AIDS and Hepatitis.
Commonly, contemporary procedures involving needle withdrawal products require a technician to use one hand to place pressure at the wound site from which a needle is being withdrawn while removing the needle apparatus with the other hand. It is common practice for a tending practitioner to give higher priority to care for the wound than is given to disposal of the needle. Such priority, for common non-safety needle apparatus, either requires an available sharps container within ready reach or another means for safe disposal without leaving the patient's side. In the case of butterfly apparatus, it is common, even for devices which are classed as safety devices, to require two hands to activate an associated safety mechanism. While no sharps container is theoretically required for such a safety mechanism, a sometimes lengthy period of time may elapse from the moment a needle is withdrawn from a patient until the safety mechanism is activated. In such cases, providing adequate care is often compounded by patient condition and mental state (e.g. in pediatrics, ICU's, burn units and psychiatric wards). Under these conditions, it is often difficult, if not impossible, to use appropriate procedures to properly dispose of a contaminated, exposed needle while caring for a patient.
Widespread knowledge and history associated with needle care and disposal problems have resulted in conception and disclosure of a large number of devices each of which represents an attempt to provide not only a solution to the problem of needle sticks, but a device which is commercially viable (i.e. cost and price competitive with currently used non-safety needle devices). A disposable medical needle and catheter placement assembly having safety enclosure means is disclosed in U.S. Pat. No. 5,176,655 issued Jan. 5, 1993 to William McCormick, et al. (McCormick). A device based upon McCormick is currently being sold under the name of ANGEL WING.TM. SAFETY NEEDLE SYSTEM by Sherwood Medical, St. Louis, Mo. 63103. The ANGEL WING.TM. device comprises a pair of flexible wing-like sections (for which the term butterfly is generally applied) extending outward from a medically disposed shroud (needle guide) which is aligned with a medical needle. In such devices, it is critical to provide stability for an extended needle as well as secure retention of a retracted needle. The Angel Wing device acquires stability for the extended needle (especially during needle insertion) from a stop provided when the wing-like sections are bent upward from a needle insertion plane and pinched together. Once insertion is complete, release of the wing-like sections disengages needle retention to free the needle of any restriction by the stop. As found in Column 6, beginning at line 11, of McCormick, "Upon completion of the intravenous or other technique, to withdraw the needle from the biological tissue, the wings 24 are held generally against the skin with fingers of one hand while the opposite hand is used to grasp the base member 34, bonded to needle 20 and pull it away from the skin puncture site in a proximal direction." When the needle is so pulled into the shroud, a leaf spring guard, distally disposed relative to the shroud, moves to retard extension of the needle to contain the needle within the shroud. Further, the needle is restrained from inadvertently being pulled proximally from the shroud by a pair of flexible straps disposed between the shroud and hub of the needle. The quoted requirement for two hand operation plus disengagement of the needle when the wing-like sections are not upwardly disposed present an opportunity for improvement in a safety device. The Angel Wing.TM. device comprises a single molded part, a metal clip and an extruded needle cover in addition to the cannula and other tubing associated with the needle itself.
Another butterfly type safety product presently commercially available is the VACUTAINER.RTM. Brand Safety-Lok.TM.Blood Collection Set distributed by Becton Dickinson VACUTAINER Systems, Becton Dickinson and Company, Franklin Lakes, N.J. 07417-1885. This butterfly Collection Set comprises a safety shield which is distally disposed over a medical needle and sharp tip and securely locked thereat as a safety guard. As is true of the Angel Wing.TM., two hands are required to engage the safety guard. This Collection Set device comprises two injection molded parts and an extruded needle cover in addition to the cannula and other tubing associated with the needle itself. This product lists U.S. Pat. No. 5,120,320 on its labeling.
Generally, other than acceptance of the type of operation offered by such devices, commercial viability is dependent upon manufacturing cost. Purchase decisions in the area in which these devices are used are very cost dependent. If gains in either improvement in safety or in labor savings are not found to make a device sufficiently competitive with contemporary even less safe items, those devices are usually not found to be commercially viable. Motivation for providing a cost competitive butterfly apparatus coupled with improved safety of use of the apparatus resulted in conception of the instant inventions disclosed herein.